Flexible NiCo2O4@carbon/carbon nanofiber electrodes fabricated by a combined electrospray/electrospinning technique for supercapacitors

[Display omitted] •The NiCo2O4@C/CNFs was fabricated by a combined electrospray/electrospinning method.•The core-shell NiCo2O4@C clusters were trapped in the carbon nanofiber net.•The specific capacitance reaches 1586 Fg−1 at 1 Ag−1 and 806 Fg−1 even at 32 Ag−1.•The capacitance retention achieves 92.5% after 5000 charge-discharge cycles. A flexible NiCo2O4@Carbon/Carbon nanofiber (NiCo2O4@C/CNFs) composite was fabricated by the combined electrospray/electrospinning technique. The NiCo2O4 clusters were coated with an amorphous carbon layer to form NiCo2O4@C core-shell structure and homogeneously trapped in the CNFs net. The NiCo2O4@C/CNFs electrodes exhibited a high specific capacitance (1586 Fg−1 at 1 Ag−1), good rate performance (51% retention even at 32 Ag−1), and superior cycling life (92.5% capacitance retention after 5000 cycles at 10 Ag−1). The combined electrospray/electrospinning technique is a promising method to produce flexible electrodes with enhanced performance.